An excavator bucket is generally made from a cast iron material, and after used for a long time, the cast iron material is worn more seriously. The cast iron material needs to be replaced while being unable to play a protection role upon wear. When a high-content alloy steel material having higher hardness is used to manufacture an excavator bucket, the high-content alloy material is extremely easy to be snapped from tension owing to relatively poor comprehensive mechanical property and relatively large brittleness caused by relatively high hardness although having better wear resistance. Moreover, the existing excavator bucket is almost formed by adopting a welding technology, without heat treatment, thus resulting in low wear resistance, easy breakage at a welding point and short service life.
Rare earth elements are generally added to improve the wear resistance of steel, but the problems of difficulty in control and limited effects are present although the rare earth elements have a certain effect on the improvement of performances, and thus it is unlikely to achieve expected mechanical property indexes in practical production.
The performances, in particular strength and toughness of steel depend on its tissue structure. The finer the grain is, and the higher the strength and the toughness of steel are. For steel, a traditional method of forming a fine grain microstructure in which an optimized combination of strength and toughness is generated is to perform thermo-mechanical treatment. Furthermore, further quality improvement has been realized by using an advanced ladle refining technology for deoxidization and desulfurization and by comprehensively reducing the oxygen content and the sulfur content of steel. However, problems in steel are not always caused by inclusions. By virtue of the capability of inclusions which can serve as effective non-uniform nucleation sites of different types of transformation products, such as ferrite and austenite, it is available to utilize a catalysis effect of the inclusions in a solidification process and in a solid state on evolution of a microstructure.
An aqueous quenching agent has the features: the aqueous quenching agent has high cooling rate through the whole cooling process, the aqueous quenching agent can promote grains to be refined with regular crystal forms in a high-temperature cooling stage, and thus facilitates to improve the service performance of workpieces, however, in a low-temperature cooling stage, problems, such as cracking, quenching deformation, occurrence of soft spots of workpieces are easily caused by overhigh cooling rate; and moreover, the problems, such as poor anti-rust performance and cleaning capability are common to the aqueous quenching agent, oxide skin is easily produced, more quenching workpieces are carried, and thus the machining technology and the production efficiency are greatly affected.